Valve for rock drills



Feb. 9 1926. 1,571,993 L. c. BAYLES VALVE FOR ROCK DRIVLLS I Original Filed oc't. 16, 1922 2 Shets-Sheet 1 INVENTOR' lieu/136130 lea HIS ATTOR Feb. 9, 1926. 1,571,993

L. c. BAYLES VALVE FORv ROCK DRILLS Original Filed Oct. 16. 1 22 2 Sheets-Sheet 2 INVENTOR.

HIS A Patented F ab. 9 1926.

TES PATENT omen.

' Lewis c. BAYLESQOF EASTON, PENNSYLVANIA, li'ss enon T INGEBLsQILL-RAND ooM PANY; or'anesnr CITY, vnwanasnra CORPORATION on NEW JERSEY.

vAtvE FOR ROCK mums.

,Original application filed oetoberlG, 1922, Serial: 1103843284 Divided and this applicatioirfiled January Tdallaolmm it may fco'izcemu Be it known that I, LEWIS C. BAYLES, a citizen of the United States. and arcsident of Easton, county of :Northampto'm, State of Pennsylvania, .have invented a certain Valvev for Rock Drills, of which the, following is a specification, accompanied by drawings v I H :This application'is" a division of my copending f application, Serial No. 594,72 filed October 15,1922, z a

This invention relatesto. rock drills, but more particularly to a differential spool type yalve having a plurality em rg foreffeetingi'th'e distribution of motive fluid to the cylinder of the rock drill; Inthe' present valve, .there are actuating faces on the valve heads, but two of the heads are larger 7 than the rema ning head, and these enlarged heads are providedvwith o opposed holding faces. @Ithas been ,found'that by forming separate aotuating'and holding faces on the heads of the valve a ,high drilling efliciency will be attained and that the valve will he quick and positive. in its action.

' -Other' objects will hereinafter appear i the following description and the accom- I pany ng drawings llustrating the nven-z tiniin its preferred forms, 4- V Figurefl 1s a dlagrammatlc' longitudlnal e1'11bodying the invention;

EigureQj isfa}v diagrammatic longitudinal; sect onal elevation iofa p'art of a rock drill showing a Imodified forniiof" the valve.

v ,Figure "3 is a diag'rammatic longitudinal sectionalelevati'on of a part of'a rock drill showing aimodified form of valve with the l reciprocating partsflin'one' position, and 40" showing the M Figure 4 is aview similar to Figure 3 position.

vReferrin to the drawin 's a )ortion of r b t: 7

fa fluid acti1atedr ockdrill isshown having: ac yhnder A and' aj-valve chestB, A pls- ,ton 0, "hav ng a reduced"cylindrical exten s'ion, is arranged within the'cylinder to re- 'ciprocate therein andde'liver" impact blows upon aydr' ll steelr'llh'e rearward end of exhaust port K.

' 'reeiprocating parts in anotherg I valve chamber with theforward and rear- 15, "1925.v Serial No. 2,553.

the cylinder is sealed by a hack head D, anda front cylinder washer E serves as a closurefor the .i'orward end of the cylinder and has alhollow here to receive the reduced extension'of the piston .C.

. A valve chamber F, having a reduced bore one end, is formed in the Valve chest and 13 in communication with a source otmotive fluid not shown) through a central inlet port H, and is provided with main exhaust ports J and K between the inlet port-ll andthe ends of the valve chamber Dis tributiojn of the motive fluid t ojthe cvlinderii and the exhaustiof motiverfluidzr therefrom is controlled by a valve L havinga centralhead O to control thefinlet port H. A face P of the head 0 is used as a 'l' olding face against which the pressure of the "motive fluid acts to hold the:

valve L in its thrown position during the admission of mot ve fluid to the forward end of the cyl nder A, The valve L also has ahead Q of the same diameter as the head 0 to control the exhaust port J and V a head R of smaller diameter to control the Disposed in one end of. the valve chamher F is a plugSto seal the chamber; The

plug S is preferablyprovided withan eX- [tension havinga face T which projects into the recess of the head R and servesas a stop for thevalver The other'end ofthe chamber F is sealed by a; plug U having a "reduced" cylindrical extension which '00- operates with the head Q, of the'valve'to' form aholdingpressure chamber V, and an actuatmg pressure chamber Wmnd is also provided with a face X to serve as a stop at the other end of the chamber for;

the valve L. r N

7 Supply passages Y and Y connect the ward ends respectively of the cylinder and passages Z and Z effect communication beband f of the valve-heads Q and R respectively are located and points in the cyltween/[he chambers in which actuating faces that the reciprocating parts are in the positions indicated in Figure 1 of the drawings. so that motive fluid entering the valve chamber I? will pass through the supply passage Y to the front end of the cylinder A and impel the piston C toward the rearward end of the cylinder. Since the diameter of the head 0 of the valve L is greater than that of the head R. the valve will re main in its thrown position until the passage Z is uncovered by the piston C, atthe same time fluid will pass through said passage into the chamber W. and acting against the actuating face Z) of the head Q will throw the valve against the face T of the plug S. thereby uncovering the exhaust port K and permitting the motive fluid in the forward end of the cylinder to escape to atmosphere while live motive fluid is admitted to the rearward end of the cylinder A through the supply passage Y.

Atthesame time motive fluid will flow through a passage 0 in the valve head 0. and acting against a holding face (Z formed on the same side of the head Q. as the actir ating face Z) will hold the valve in its thrown position until the piston (l uncovers the passage Z. thereby permitting live motive fluid to enter the chamber 0. and acting against the actuating face 7' of the head R will overcome the pressure of the motive fluid within the holding chamber V and throw the valve to the position indicated in the drawings. Simultaneously the motive fluid in the rearward end of the cylinder will escape through the supply passage Y, and though the exhaust port J to atmosphere. and the for ard end of the cylinderis. again subject to live. motive fluid. thus completing the cycle of operations.

In Figure l a modified form of a differential spool valve shown. having separate actuating and holding faces. In this instance. the uilve L is provided at one. end with a reduced cylindrical extension having a holding face 12 This extension is adapted to reciprocate within the bore j of the plug 7.. said bore serving as a pressure chamber. which is in comnninication with the rearward end of the cylinder. A face 0 of the valve head Q. is utilized as an actuating face against which live motive fluid will act to overcome the pressure against the face. I. of the. central head 0 to throw the *alve to the other limiting position.

The valve If is preferably made as light in weight as possible without sacrificing strength. To this end the middle head 0 and one outer head Q. are recessed on the sides and a central bore is formed part way through the center of the valve. In this instance. the admission and exhaust of motive fluid. and the distribution thereof are effected in the same manner as in Figure 1, while the ports and passages for re ciprocating the piston C and the valve L are also like those described in connection with Figure 1.

In the modification illustrated in Figures 3 and t, a differential spool type valve L. having separate actuating and holding faces, is shown in the valve chamber F. The central head 0' and the head Q/ are of the same diameter with relation to each other, and embody the characteristics of the corresponding heads described in Figure 1.. In this instance the smaller valve head R is formed solid and is provided with an unbroken actuating face f. The admission and exhaust of motive fluid, and the distribution thereof. are effected in the same manncr as described in connection with Figure 1.

I claim:

'1. In a rock drill. the combination of a cylinder. a piston within the cylinder, a

valve chest having a valve chamber and an inletport communicating with the valve chamber. exhaust ports connecting the valve chamber with the atmosphere, and a. valve within the chamber to control the ports. said valve having a centralhead with a holding face. an end head of the samediameter with separate holding and actuating faces and another end head of smaller diameter with an actuating face to enable pressure fluid acting against the last said actuating face to overcome pressure fluid acting against the holding face of the other end head.

In a rock drill, the combination of a.

cylinder. a piston within the cylii'idcr. a valve chest having a'valve chamber and an inlet port. connnunicating with the valve chamber, exhaust ports connecting the valve chamber with the atmosphere. a valve within the chamber to control the ports,.said valve having a central head with a holding face, an end head of smaller diameter with an actuating face against which pressure fluid may act for throwing the valve against pressure acting in the opposite direction and another end head with separate actuating and holding faces for retau'niln, the valve and holding said valve. and means for sealing the ends of the chambers, one of saidsealing. means cooperating with one end of thevalve for forming separate actuating and holding pressure chambers.

3. In a rock drill, the con'ibinat ion ofa cylinder. a piston within the cylinder. a valve chest having a valve chamber, an inlet port connnunicating with the valve chamber. and exhaust" ports connecting the valve chamber with the atmosphere. a-valvewithin the chamber to control the ports. said *alve having a central head with a holding face. an end head of smaller .diameter with an actuating face to enable said valve to be thrown against pressure acting against the opposite end of the valve and another end head. with separate actuating and holding faces for throwing the valve and holding said valve in thrown position, and plugs to seal the ends of the chambers, one of said plugs cooperating with one end of the valve for forming separate actuating and holding pressure chambers, said valve chest being provided with ports and passages for admitting motive fluid to the cylinder and exhausting it therefrom and for 10 actuating and holding the valve.

In testimony whereof I have signed this specification.

LEWIS G. BAYLES. 

